This invention relates to a hand firearm (small arm) comprising a breech block or lock consisting essentially of a sliding element or breech block carrier displaceable against the bias of a locking or return spring and a closing element or breech block traversed by an ignition pin or primer, being supported in the breech block carrier and movable relative thereto, as well as a barrel firmly connected with a stock or the like.
In hand firearms, having a breech block which is movable against the force of a return spring, the return speed (recoil) is inversely proportional to the mass of the breech block, in accordance with the theorem of momentum. Therefore, in order to decrease the return speed, it is necessary to increase the mass of the breech block. However, this is impracticable in view of the tendency of the decreasing weight and dimensions of small arms. Hence, when the mass of the lock is reduced, an increased return speed is to be expected, which means a considerably augmented energy of recoil (kick), which increases with the square of the return speed, and is extremely detrimental when shooting off the hand arm. In a known hand firearm, the return spring is mounted in the breech block carrier for relative displacement thereto in longitudinal as well as in transverse direction and is supported in the breech block carrier via a rocking lever. The breech block abuts initially without play against an oblique stop of the stock or the like. In order to delay the rising of the breech block, or, respectively, its lifting off this stop, which movement initially results in a desirable transmission of force to the stock or the like at the instant of ignition, use is made of the inertia of the breech block carrier by way of the rocking lever. However, this entails the drawback that the return speed of the slider is additionally increased by the rocking lever, so that the recoil is not reduced.